I used to keep this species for a while many years ago. They are a magnificent looking monitor lizard. When i kept Varanus yuwonoi i had a cage that measured 250x270x110 ( long X high X deep). I housed a pair in that cage and they would really use the height of the cage, often hiding inside cork tubes in the upper part of the cage. The cage contained a large water container, big enough for the monitors to be able to submerge themselves. Lot of thick branches and cork tubes mqde out the decorations in the cage. And a basking area made from several solar raptor flood bulbs, to make it large enough for the monitors to warm up their bodies.Lighting in the cage was made up by some t5 ho tubes and a hqi lamp.Their main diet was made from chicks, mice, rats, chicken heart. They where offered grasshoppers every week, and dubias as well (i dont recall them ever eating dubia).